JP2012052249A - Composite spun yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite spun yarn comprising a meta-type wholly aromatic polyamide fiber and a polyester fiber, having a suppressed hue difference between the meta-type wholly aromatic polyamide fiber and the polyester fiber caused by the fading color in the meta-type wholly aromatic polyamide fiber.SOLUTION: A meta-type wholly aromatic polyamide fiber using a highly hydrophobic ultraviolet absorber and having a specific physical property is formed, and a composite spun yarn is formed by using the meta-type wholly aromatic polyamide fiber. In other words, a meta-type wholly aromatic polyamide fiber including a ultraviolet absorber with a solubility in water of less than 0.04 mg/L, having a dyeing rate in dyed fiber of 90% or more, and having a light resistance retention before and after carrier dyeing of 80% or more is used, so as to form a composite spun yarn comprising a polyester fiber and the meta-type wholly aromatic polyamide fiber.

Description

  The present invention relates to a composite spun yarn composed of a meta-type wholly aromatic polyamide fiber and a polyester fiber.

Meta-type wholly aromatic polyamide fibers such as polymetaphenylene terephthalamide fibers exhibit excellent heat resistance and flame resistance because most of the molecular skeleton is composed of aromatic rings. Taking advantage of these properties, meta-type wholly aromatic polyamide fibers have recently been rapidly expanding their use in fields such as bedding, clothing and interiors that make use of flame resistance and flame resistance. And in these fields of protective clothing, bedding, interior, etc., colored fibers are required from the viewpoint of visibility and aesthetics, and at the same time, comfort and form retention are required.
Therefore, for the purpose of imparting functional characteristics such as comfort and form retention, a composite spun yarn in which polyester short fibers and wholly aromatic polyamide fibers are mixed is disclosed (see Patent Documents 1 and 2).

However, the wholly aromatic polyamide fibers used in the composite spun yarns described in Patent Documents 1 and 2 have a very poor light resistance of the obtained colored fibers when dyed with a basic dye. There is a problem that a hue difference occurs between the two, and the aesthetic appearance of the entire spun yarn is impaired.
Here, as a method of obtaining a colored wholly aromatic polyamide fiber with high light resistance, an aromatic polyamide solution is subjected to dry or wet spinning, the obtained fiber is washed, and then dried before being dried. A method of impregnating an aqueous dispersion of the above has been proposed (see Patent Document 3). However, the fiber obtained by this method tends to cause the UV shielding material to fall off due to the influence of the carrier at the time of carrier dyeing, and as a result, the light resistance of the colored fiber is still unsatisfactory.

  In addition, as another method for obtaining highly light-resistant wholly aromatic polyamide fibers, wholly aromatic polyamide fibers capable of non-carrier dyeing have also been studied. For example, dyeing aid alkyl benzene sulfonic acid onium salt and hindered amine light resistance A meta-type wholly aromatic polyamide fiber containing an agent is disclosed (see Patent Document 4). However, since the fiber is dyed non-carrier, it is difficult for the light-proofing agent to fall off during dyeing. However, the addition of the onium salt increases the production cost of the fiber and reduces the flame retardancy of the resulting fiber. It was necessary to further add a flame retardant and the like.

  Therefore, none of the meta-type wholly aromatic polyamide fibers used for composite spun yarns with polyester short fibers satisfying a good balance between excellent mechanical strength and light resistance. A composite composed of meta-type wholly aromatic polyamide fiber and polyester fiber, in which the hue difference between meta-type wholly aromatic polyamide fiber and polyester fiber, which is caused by discoloration of the type-type wholly aromatic polyamide fiber, is suppressed The spun yarn was not yet obtained.

JP 2004-143605 A Japanese Patent Laid-Open No. 2000-256828 JP 49-075824 A JP 2003-239136 A

  The present invention has been made in view of the above-described background art, and the object of the present invention is to provide a meta-type wholly aromatic polyamide fiber and a polyester that are generated due to discoloration of the meta-type wholly aromatic polyamide fiber. An object of the present invention is to provide a composite spun yarn comprising a meta-type wholly aromatic polyamide fiber and a polyester fiber, in which a hue difference with the fiber is suppressed.

  The present inventors have intensively studied to solve the above problems. As a result, if a highly hydrophobic ultraviolet absorber is used and a meta-type wholly aromatic polyamide fiber having specific physical properties is formed and a composite spun yarn is formed using the meta-type wholly aromatic polyamide fiber, The present inventors have found that the above problems can be solved and have completed the present invention.

  That is, the present invention is a composite spun yarn composed of a meta-type wholly aromatic polyamide fiber and a polyester fiber, and the meta-type wholly aromatic polyamide fiber constituting the composite spun yarn has a solubility in water of 0.04 mg / L. The composite spun yarn includes an ultraviolet absorber that is less than 90%, has a dyed fiber dyeing rate of 90% or more, and has a light resistance retention of 80% or more before and after carrier dyeing.

  The meta-type wholly aromatic polyamide fiber constituting the composite spun yarn of the present invention can be dyed in various hues by carrier dyeing, and can prevent the light-resistant agent from falling off during dyeing. Is a meta-type wholly aromatic polyamide fiber having sufficient light resistance. For this reason, the composite spun yarn of this invention can suppress the color spot which generate | occur | produces by the difference in the light fading of a polyester fiber and a meta-type wholly aromatic polyamide fiber. Therefore, the composite spun yarn of the present invention is extremely useful in fields where excellent heat resistance, flame resistance, and flame resistance are required, and is particularly suitably used as a heat-resistant protective clothing worn by firefighters during fire fighting operations. be able to.

<Composite spun yarn>
The composite spun yarn of the present invention comprises a meta-type wholly aromatic polyamide fiber and a polyester fiber.

[Composition ratio]
The content of the meta-type wholly aromatic polyamide fiber in the composite spun yarn is 50 to 90% by mass with respect to the entire composite spun yarn, and the content of the polyester fiber is 50 to 10% by mass with respect to the entire composite spun yarn. It is preferable that The content of the meta-type wholly aromatic polyamide fiber is preferably 50% by mass or more with respect to the total mass of the composite spun yarn from the viewpoint of flameproofness, and 90% by mass or less from the viewpoint of wearing feeling. preferable.

  The content of the meta-type wholly aromatic polyamide fiber is more preferably 65 to 90% by mass, most preferably in the range of 75 to 90% by mass with respect to the entire composite spun yarn, and the polyester fiber content. Is more preferably 10 to 35% by mass, and most preferably 10 to 25% by mass, based on the entire composite spun yarn.

<Polyester fiber>
In the composite spun yarn of the present invention, the polyester fiber mixed with the meta-type wholly aromatic polyamide fiber is not particularly limited, but terephthalic acid is the main dicarboxylic acid component, and at least one glycol, preferably ethylene glycol. It is preferably a fiber made of polyester having at least one alkyl glycol selected from trimethylene glycol, tetramethylene glycol and the like as a main glycol component. In addition, the polyester fiber may contain an optional additive such as a catalyst, an anti-coloring agent, a heat-resistant agent, a flame retardant, an antioxidant, and inorganic particles as necessary.

<Meta type wholly aromatic polyamide fiber>
The meta type wholly aromatic polyamide fiber mixed with the polyester fiber in the composite spun yarn of the present invention will be described below.

[Physical properties of meta-type wholly aromatic polyamide fibers]
[Residual solvent amount]
Since the meta-type wholly aromatic polyamide fiber is usually produced from a spinning stock solution in which a polymer is dissolved in an amide solvent, the solvent necessarily remains in the fiber. However, in the meta-type wholly aromatic polyamide fiber used in the present invention, the amount of the solvent remaining in the fiber is preferably 0.1% by mass or less with respect to the fiber mass. The content is preferably 0.1% by mass or less, and more preferably 0.08% by mass or less.

  When the solvent remains in the fiber in excess of 0.1% by mass with respect to the fiber mass, the residual solvent volatilizes during processing and use in a high temperature atmosphere exceeding 200 ° C. Inferior to environmental safety. Moreover, since the strength is remarkably reduced by destroying the molecular structure, it is not preferable.

In order to reduce the residual solvent amount of the fibrils to 0.1% by mass or less, in the fiber production process, the components or conditions of the coagulation bath are adjusted so as to obtain a coagulation form having no skin core, and plasticization is performed at a specific magnification. Stretching is performed.
In addition, the “residual solvent amount of the fibril” in the present invention refers to a value obtained by the following method.

(Measurement method of residual solvent amount)
About 8.0 g of fibrils are collected, dried at 105 ° C. for 120 minutes, allowed to cool in a desiccator, and the fiber mass (M1) is weighed. Subsequently, this fiber is subjected to reflux extraction using a Soxhlet extractor in methanol for 1.5 hours to extract an amide solvent contained in the fiber. The fiber after extraction is taken out, vacuum-dried at 150 ° C. for 60 minutes, allowed to cool in a desiccator, and the fiber mass (M2) is weighed. The amount of solvent (amide solvent mass) N (%) remaining in the fiber is calculated by the following formula using M1 and M2 obtained.
N (%) = [(M1-M2) / M1] × 100

[Dyeing rate of dyed fiber]
In the meta-type wholly aromatic polyamide fiber used in the present invention, the dyeing rate of the dyed fiber is 90% or more, and more preferably 92% or more. When the dyeing rate of the dyed fiber is less than 90%, it is not preferred in terms of aesthetics, and it cannot be dyed to a desired hue.
“Dyeing” for obtaining “dyeing rate” is dyeing by the following dyeing method.

(Dyeing method)
Cationic dye (product name: Kayacryl Blue GSL-ED (B-54), manufactured by Nippon Kayaku Co., Ltd.) 6% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dispersion A dyeing solution containing 0.5 g / L of a dyeing assistant (manufactured by Meisei Chemical Co., Ltd., trade name: Disper TL) is prepared as an agent.

Subsequently, the dyeing treatment is performed at 120 ° C. for 60 minutes with the bath ratio of the fiber and the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L The dyed fiber is obtained by carrying out reduction washing at 80 ° C. for 20 minutes at a bath ratio of 1:20, and drying after washing with water.
The “dyeing rate” in the present invention refers to a value obtained by the following method.

(Dyeing rate)
Add the same volume of dichloromethane as this dyeing residual solution to the dyeing residual solution dyed fibrils to extract the residual dye. Subsequently, with respect to the extract, the absorbance at wavelengths of 670 nm, 540 nm, and 530 nm was measured, respectively, and the dye concentration of the extract was determined from the calibration curve of the above three wavelengths prepared from a dichloromethane solution with a known dye concentration in advance. Let the average value of density | concentration be the dye density | concentration (C) of an extract. Using the dye concentration (Co) before dyeing, the value obtained by the following equation is defined as the dyeing rate (U).
Dyeing rate (U) = [(Co−C) / Co] × 100

  The dyeing rate of the dyed fibers of the meta-type wholly aromatic polyamide fiber is determined by adjusting the conditions of the coagulation bath so as to form a coagulation form having no skin core in the coagulation process in the production method described later, Can be controlled by optimizing the crystallinity of the fiber. In order to set the dyeing rate of the dyed fiber to 90% or more, the coagulation liquid is an aqueous solution having an NMP concentration of 45 to 60% by mass, the bath liquid temperature is 10 to 35 ° C., and the dry heat treatment temperature is the glass transition temperature of the fiber ( The temperature may be in the range of 260 to 330 ° C., which is equal to or higher than Tg).

[Fracture strength and elongation at break of fibrils]
The breaking strength of the fibrils (fibers before dyeing) of the meta-type wholly aromatic polyamide fiber used in the present invention is preferably 2.5 cN / dtex or more. It is more preferably 2.7 cN / dtex or more, and particularly preferably 3.0 cN / dtex or more. When the breaking strength is less than 2.5 cN / dtex, the fiber is broken in a post-processing step such as spinning, and the passability is deteriorated.

  Moreover, it is preferable that the elongation at break of the fibrils (fibers before dyeing) of the meta-type wholly aromatic polyamide fibers used in the present invention is 30% or more. It is more preferably 35% or more, and particularly preferably 40% or more. When the elongation at break is less than 30%, passability in post-processing steps such as spinning deteriorates, which is not preferable.

The “breaking strength and breaking elongation” in the present invention refers to values obtained by measurement under the following conditions using model number 5565 manufactured by Instron, based on JIS L 1015.
(Measurement condition)
Grasp interval: 20mm
Initial load: 0.044 cN (1/20 g) / dtex
Tensile speed: 20 mm / min

  The “breaking strength” of the meta-type wholly aromatic polyamide fiber used in the present invention is controlled by optimizing the draw ratio in the plastic drawing bath drawing step and the heat treatment temperature in the dry heat treatment step in the production method described later. Can do. In order to set the breaking strength to 2.5 cN / dtex or more, the draw ratio may be set to 3.5 to 5.0 times, and the dry heat treatment temperature may be set to a range of 260 to 330 ° C.

  The “breaking elongation” of the meta-type wholly aromatic polyamide fiber used in the present invention can be controlled by optimizing the coagulation bath conditions in the coagulation step in the production method described later. In order to achieve 30% or more, the coagulating liquid may be an aqueous solution having an NMP concentration of 45 to 60% by mass, and the bath liquid temperature may be 10 to 35 ° C.

[Light resistance retention before and after carrier dyeing]
The meta-type wholly aromatic polyamide fiber used in the present invention has a light resistance retention of 80% or more before and after carrier dyeing. It is preferably 85% or more, and particularly preferably 90% or more. A low light resistance retention before and after carrier dyeing means that the light-resistant agent is often removed during carrier dyeing. If the weather resistance retention before and after carrier dyeing is less than 80%, the product after dyeing This is not preferable because the light resistance effect is not sufficiently exhibited.
The “light resistance retention” in the present invention refers to a value obtained by the following method.

(How to obtain light resistance retention)
As an evaluation of light resistance, light discoloration chromaticity (ΔE *) is obtained using light-irradiated cotton and unirradiated cotton irradiated at 63 ° C. for 24 hours with a carbon arc fade meter. As the light resistance change chromaticity (ΔE *), first, the diffuse reflectance in the -10-degree field of view is measured using the light source D65, and the lightness index L * value, the chromaticness index a *, b are obtained by normal calculation processing. * The value is calculated, and the obtained value is used to obtain the value according to the following formula in accordance with JIS Z-8730.
[Formula 1]
ΔE * = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2
The “light fastness retention” is the value calculated by the following equation by obtaining the above light fast discoloration chromaticity (ΔE *) for cotton before and after dyeing.
[Formula 2]
Lightfastness retention (%) = 100− (post-staining ΔE * −pre-staining ΔE *) / pre-staining ΔE * x100
“Dyeing” in the evaluation of “light resistance retention” is dyeing without using a dye by the following method.

(Dyeing method)
Without using dye, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dyeing assistant (manufactured by Meisei Chemical Industry Co., Ltd., trade name: Disper TL) 0.5 g / A staining solution containing L is prepared.
Subsequently, the dyeing treatment is performed at 120 ° C. for 60 minutes with the bath ratio of the fiber and the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L The dyed fiber is obtained by carrying out reduction washing at 80 ° C. for 20 minutes at a bath ratio of 1:20, and drying after washing with water.

[Single yarn fineness]
The single fiber fineness of the meta-type wholly aromatic polyamide fiber used in the present invention is preferably 0.50 to 6.0 dtex, more preferably 0.8 to 5.5 dtex. In the present invention, two or more kinds of fibers having different finenesses may be mixed and used.

[Fiber length]
The fiber length of the meta-type wholly aromatic polyamide fiber used in the present invention may be set as appropriate according to the form of the intended composite spun yarn, and may be either a long fiber or a short fiber. When spinning as a short fiber, it is preferable that the fiber length of the short fiber to which crimps are applied in advance is in a range of 31 to 76 mm.

[Configuration of meta-type wholly aromatic polyamide]
The meta-type wholly aromatic polyamide constituting the meta-type wholly aromatic polyamide fiber used in the present invention is composed of a meta-type aromatic diamine component and a meta-type aromatic dicarboxylic acid component. Other copolymer components such as the para type may be copolymerized within a range not impairing the above.

Particularly preferred for use in the present invention is a meta-type wholly aromatic polyamide mainly composed of a metaphenylene isophthalamide unit from the viewpoints of mechanical properties, heat resistance and flame retardancy.
As the meta-type wholly aromatic polyamide composed of metaphenylene isophthalamide units, the metaphenylene isophthalamide units are preferably 90 mol% or more of the total repeating units, more preferably 95 mol% or more, particularly preferably. 100 moles.

[Raw material for meta-type wholly aromatic polyamide]
(Meta-type aromatic diamine component)
Examples of the meta-type aromatic diamine component used as a raw material for the meta-type wholly aromatic polyamide include metaphenylene diamine, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl sulfone, and the like, halogens in these aromatic rings, Examples of derivatives having a substituent such as an alkyl group having 1 to 3 carbon atoms, such as 2,4-toluylenediamine, 2,6-toluylenediamine, 2,4-diaminochlorobenzene, 2,6-diaminochlorobenzene, etc. can do. Of these, metaphenylenediamine alone or a mixed diamine containing metaphenylenediamine in an amount of 85 mol% or more, preferably 90 mol% or more, particularly preferably 95 mol% or more is preferable.

(Meta-type aromatic dicarboxylic acid component)
Examples of the raw material of the meta type aromatic dicarboxylic acid component constituting the meta type wholly aromatic polyamide include a meta type aromatic dicarboxylic acid halide. Examples of the meta-type aromatic dicarboxylic acid halide include isophthalic acid halides such as isophthalic acid chloride and isophthalic acid bromide, and derivatives having substituents such as halogen and alkoxy groups having 1 to 3 carbon atoms on the aromatic ring, such as 3 -Chloroisophthalic acid chloride etc. can be illustrated. Of these, isophthalic acid chloride itself or a mixed carboxylic acid halide containing isophthalic acid chloride in an amount of 85 mol% or more, preferably 90 mol% or more, particularly preferably 95 mol% or more is preferable.

[Method for producing meta-type wholly aromatic polyamide]
The production method of the meta-type wholly aromatic polyamide is not particularly limited. For example, it is produced by solution polymerization or interfacial polymerization using a meta-type aromatic diamine component and a meta-type aromatic dicarboxylic acid chloride component as raw materials. be able to.
In addition, the molecular weight of the meta-type wholly aromatic polyamide used in the present invention is not particularly limited as long as it can form fibers. In general, in order to obtain a fiber having sufficient physical properties, a polymer having an intrinsic viscosity (IV) measured in a concentrated sulfuric acid at 30 ° C. with a polymer concentration of 100 mg / 100 mL sulfuric acid is in a range of 1.0 to 3.0. Appropriate polymers in the range of 1.2 to 2.0 are particularly preferred.

<Method for producing meta-type wholly aromatic polyamide fiber>
The meta-type wholly aromatic polyamide fiber used in the present invention uses the meta-type wholly aromatic polyamide obtained by the above production method, for example, a spinning solution preparation process, spinning / coagulation process, plastic drawing described below. It is manufactured through a bath stretching process, a washing process, a relaxation process, and a heat treatment process.

[Spinning liquid preparation process]
In the spinning solution preparation step, the meta type wholly aromatic polyamide is dissolved in an amide solvent, and an ultraviolet absorber is added to prepare a spinning solution (meta type wholly aromatic polyamide polymer solution). In the production of the meta-type wholly aromatic polyand fiber used in the present invention, it is important to include a specific ultraviolet absorber in the spinning solution in the spinning solution preparation step. By forming fibers from a spinning solution containing an ultraviolet absorber, elution of the ultraviolet absorber during carrier dyeing can be suppressed.

In preparing the spinning solution, an amide solvent is usually used, and examples of the amide solvent used include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), and dimethylacetamide (DMAc). be able to. Of these, NMP or DMAc is preferably used from the viewpoints of solubility and handling safety.
The concentration of the solution may be appropriately selected from the viewpoint of the coagulation rate and the solubility of the polymer in the next spinning and coagulation step. For example, the polymer is polymetaphenylene isophthalamide and the solvent is NMP. In the case of, it is usually preferred to be in the range of 10 to 30% by mass.

(UV absorber)
The ultraviolet absorber used in the present invention is highly hydrophobic and needs to have a solubility in water of less than 0.04 mg / L. If it is 0.04 mg / L or more, the ultraviolet absorber is eluted during carrier dyeing, and the light resistance after dyeing is undesirably lowered.
In addition, the ultraviolet absorber used in the present invention is a compound that efficiently shields light around 360 nm, which is the photodegradation characteristic wavelength of the meta wholly aromatic polyamide, and has almost no absorption in the visible region. preferable.

  Accordingly, the ultraviolet absorber used in the present invention is preferably a specific substituted benzotriazole, specifically, 2- (2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol, 2- [5-Chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- [2H-benzotriazol-2-yl] -4-6-bis ( 1-methyl-1-phenylethyl) phenol, 2- [2H-benzotriazol-2-yl] -4- (1,1,3,3-tetramethylbutyl) phenol, and the like. Among these, 2- [2H-benzotriazol-2-yl] -4-6-bis (1-methyl-1-phenylethyl) phenol is highly hydrophobic and has a small absorption in the visible region. Is particularly preferred.

The content of the ultraviolet absorber with respect to the meta type wholly aromatic polyamide fiber is preferably in the range of 3.0% by mass to 6.5% by mass with respect to the total mass of the meta type wholly aromatic polyamide fiber, and more preferably. Is in the range of 4.5 mass% to 6.5 mass%. When the amount is less than 3.0% by mass, the light resistance effect is not sufficiently exhibited, which is not preferable. When the amount is more than 6.5% by mass, physical properties of the obtained raw cotton are deteriorated, which is not preferable.
The mixing method of the meta type wholly aromatic polyamide and the UV absorber is a method of mixing and dissolving the UV absorber in the solvent and adding the meta type wholly aromatic polyamide solution thereto, or the UV absorber is added to the meta type wholly aromatic. The method of dissolving in a polyamide solution is not particularly limited. The spinning solution thus obtained is formed into a fiber through the following steps.

[Spinning and coagulation process]
In the spinning / coagulation step, the spinning solution (meta-type wholly aromatic polyamide polymer solution) obtained above is spun into a coagulating solution and coagulated.
The spinning device is not particularly limited, and a conventionally known wet spinning device can be used. Moreover, the number of spinning holes, the arrangement state, the hole shape and the like of the spinneret are not particularly limited as long as they can be stably wet-spun. For example, the number of holes is 500 to 30,000, and the spinning hole diameter is 0.05. A multi-hole spinneret for ˜0.2 mm sufu may be used.
The temperature of the spinning solution (meta-type wholly aromatic polyamide polymer solution) when spinning from the spinneret is suitably in the range of 10 to 90 ° C.

As a coagulation bath used for obtaining the fiber used in the present invention, an aqueous solution containing an inorganic salt and having an NMP concentration of 45 to 60% by mass is used in the temperature range of the bath solution of 10 to 35 ° C. If the NMP concentration is less than 45% by mass, the skin has a thick structure, the cleaning efficiency in the cleaning process is lowered, and it becomes difficult to make the residual solvent amount of the fibrils 0.1% by mass or less. Further, when the NMP concentration exceeds 60% by mass, uniform solidification cannot be performed until the inside of the fiber is reached, and therefore, it becomes difficult to make the residual solvent amount of the fibrils 0.1% by mass or less. . In addition, the range of 0.1-30 seconds is suitable for the immersion time of the fiber in a coagulation bath.
By setting the components or conditions of the coagulation bath as described above, the skin formed on the fiber surface can be made thin, and the structure can be made uniform to the inside of the fiber. The breaking elongation of the obtained fiber can be improved.

[Plastic stretching bath stretching process]
In the plastic drawing bath drawing step, the fiber is drawn in the plastic drawing bath while the fiber obtained by coagulation in the coagulation bath is in a plastic state.
It does not specifically limit as a plastic drawing bath liquid, A conventionally well-known bath liquid can be employ | adopted.

  In order to obtain the fiber used in the present invention, the draw ratio in the plastic drawing bath needs to be in the range of 3.5 to 5.0 times, more preferably in the range of 3.7 to 4.5 times. And By plastic stretching in a plastic stretching bath in a specific magnification range, solvent removal from the coagulated yarn can be promoted, and the residual solvent amount of the fibril can be reduced to 0.1% by mass or less.

When the draw ratio in the plastic drawing bath is less than 3.5 times, the solvent removal from the coagulated yarn becomes insufficient, and it is difficult to reduce the residual solvent amount of the fibrils to 0.1% by mass or less. It becomes. Further, the breaking strength becomes insufficient, and handling in a processing process such as a spinning process becomes difficult. On the other hand, when the draw ratio exceeds 5.0 times, single yarn breakage occurs, resulting in poor production stability.
The temperature of the plastic stretching bath is preferably in the range of 10 to 90 ° C. When the temperature is preferably in the range of 20 to 90 ° C, the process condition is good.

[Washing process]
In the washing step, the fiber drawn in the plastic drawing bath is thoroughly washed. Washing is preferably performed in multiple stages because it affects the quality of the resulting fiber. In particular, the temperature of the cleaning bath in the cleaning step and the concentration of the amide solvent in the cleaning bath liquid affect the state of extraction of the amide solvent from the fibers and the state of penetration of water from the cleaning bath into the fibers. For this reason, it is preferable to control the temperature condition and the concentration condition of the amide solvent by setting the washing process in multiple stages for the purpose of bringing them into an optimum state.

The temperature condition and the concentration condition of the amide solvent are not particularly limited as long as the quality of the finally obtained fiber can be satisfied, but if the initial washing bath is at a high temperature of 60 ° C. or higher, water Intrusion into the fiber occurs at a stretch, generating huge voids in the fiber, leading to quality degradation. For this reason, it is preferable that the first washing bath has a low temperature of 30 ° C. or lower.
When the solvent remains in the fiber, environmental safety in processing of the product using the fiber and use of the product formed using the fiber is not preferable. For this reason, it is preferable that the solvent amount contained in the fiber used for this invention is 0.1 mass% or less, More preferably, it is 0.08 mass% or less.

[Dry heat treatment process]
In the dry heat treatment step, the fiber that has undergone the washing step is dried and heat treated. Although it does not specifically limit as a method of dry heat processing, For example, the method of using a hot roller, a hot plate, etc. can be mentioned. By performing the dry heat treatment, finally, the meta type wholly aromatic polyamide fiber used in the present invention can be obtained.

  In order to obtain the fiber used for this invention, it is necessary to make the heat processing temperature in a dry heat treatment process into the range of 260-330 degreeC, and it is more preferable to set it as the range of 270-310 degreeC. When the heat treatment temperature is less than 260 ° C., the crystallization of the fibers becomes insufficient, the shrinkage of the fibers becomes high, and the handling in the dyeing process becomes difficult. On the other hand, when the temperature exceeds 330 ° C., the crystallization of the fibers becomes too large, and the dyeability is greatly reduced. Moreover, making dry-heat-treatment temperature into the range of 260-330 degreeC contributes to the improvement of the breaking strength of the fiber obtained.

[Crimping process]
The meta-type wholly aromatic polyamide fiber that has been subjected to the dry heat treatment may be further crimped as necessary. Further, after the crimping process, it may be cut into an appropriate fiber length and provided to the next step. In some cases, it may be wound up as a multifilament yarn.

[Cut method]
When the meta-type wholly aromatic polyamide fiber is cut, the cutting method is not particularly limited, and a known method can be adopted. For example, the method etc. which cut a fiber into predetermined fiber length using a guillotine cutter and a rotary disc cutter are mentioned.

<Production method of composite spun yarn>
In the composite spun yarn of the present invention, the method of mixing the meta-type wholly aromatic polyamide fiber and the polyester fiber is not particularly limited, and blended fiber (homogeneous blended fiber, core yarn blended fiber etc.), mixed fiber (core sheath) Any mixing method such as composite yarn, covering yarn, etc.), woven or knitted can be used. Among these, uniform blending or mixing as a core-sheath type composite yarn in which a polyester fiber is disposed in the core and a meta-type wholly aromatic polyamide fiber is disposed in the sheath is preferable.
The composite spun yarn of the present invention can be produced by a known spinning method, and examples thereof include cotton spinning, silk spinning, perlock, and wool spinning.

<Dyeing process>
When dyeing the composite spun yarn of the present invention, existing synthetic fiber dyeing equipment can be used. As the dye used for the dyeing treatment, a cationic dye that easily penetrates into a dense structure and has a high dyeing rate is preferable.
Further, in order to dye the composite spun yarn of the present invention, it is necessary to use a carrier that is a dyeing aid for the meta-type wholly aromatic polyamide fiber. When the carrier is not used, the dye cannot sufficiently penetrate into the dense structure of the fiber, and the dyeing rate is lowered, which is not preferable.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and the like, but the present invention is not limited to these examples and the like.

<Measurement method>
Each physical property value in Examples and Comparative Examples was measured by the following method.

[Fineness]
Based on JIS L 1015, the measurement based on the A method of positive fineness was implemented, and it described with the apparent fineness.

[Break strength, elongation at break]
Based on JIS L1015, it measured on condition of the following using the model number 5565 by Instron.
(Measurement condition)
Grasp interval: 20mm
Initial load: 0.044 cN (1/20 g) / dtex
Tensile speed: 20 mm / min

[Dyeing rate of meta-type wholly aromatic polyamide fiber]
Dichloromethane having the same volume as that of the dyeing residual liquid was added to the dyeing residual liquid obtained by dyeing the meta-type wholly aromatic polyamide raw cotton, and the residual dye was extracted. Subsequently, with respect to the extract, the absorbance at wavelengths of 670 nm, 540 nm, and 530 nm was measured, respectively, and the dye concentration of the extract was determined from the calibration curve of the above three wavelengths prepared from a dichloromethane solution with a known dye concentration in advance. The average value of the concentration was defined as the dye concentration (C) of the extract. Using the dye concentration (Co) before dyeing, the value obtained by the following formula was used as the dyeing rate (U).
Dyeing rate (U) = [(Co−C) / Co] × 100
In addition, as the “dyeing” for obtaining the “dyeing rate”, the following dyeing method was carried out.

(Method for dyeing meta-type wholly aromatic polyamide raw cotton)
Cationic dye (product name: Kayacryl Blue GSL-ED (B-54), manufactured by Nippon Kayaku Co., Ltd.) 6% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dispersion A dyeing solution containing 0.5 g / L of a dyeing assistant (made by Meisei Chemical Co., Ltd., trade name: Disper TL) was prepared as an agent.
Subsequently, a dyeing treatment was performed at 120 ° C. for 60 minutes with a bath ratio of the meta-type wholly aromatic polyamide raw cotton and the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used to carry out reduction washing at a bath ratio of 1:20 at 80 ° C. for 20 minutes, and after washing with water, dried to obtain a meta-type wholly aromatic polyamide raw cotton.

[Residual solvent amount of meta-type wholly aromatic polyamide fibrils]
About 8.0 g of meta-type wholly aromatic polyamide raw cotton was collected, dried at 105 ° C. for 120 minutes, allowed to cool in a desiccator, and the fiber mass (M1) was weighed. Subsequently, this fibril was subjected to reflux extraction using a Soxhlet extractor in methanol for 1.5 hours to extract an amide solvent contained in the fiber. The fiber after extraction was taken out, vacuum-dried at 150 ° C. for 60 minutes, allowed to cool in a desiccator, and the fiber mass (M2) was weighed. The amount of solvent (amide solvent mass) N (%) remaining in the fiber was calculated by the following formula using the obtained M1 and M2.
N (%) = [(M1-M2) / M1] × 100

[Intrinsic viscosity (IV)]
The meta-type wholly aromatic polyamide polymer was isolated from the polymer solution and dried, and then measured in concentrated sulfuric acid at a polymer concentration of 100 mg / 100 mL sulfuric acid at 30 ° C.

[Light resistance retention before and after dyeing of meta-type wholly aromatic polyamide fiber]
As an evaluation of light resistance, meta-type wholly aromatic polyamide raw cotton was irradiated with a carbon arc fade meter at 63 ° C. for 24 hours, and light-resistant discoloration chromaticity (ΔE *) was obtained using a light irradiated portion and an unirradiated portion. As the light resistance change chromaticity (ΔE *), first, the diffuse reflectance in the -10-degree field of view is measured using the light source D65, and the lightness index L * value, the chromaticness index a *, b are obtained by normal calculation processing. * A value was calculated, and the obtained value was used to obtain the value according to the following formula in accordance with JIS Z-8730.
[Formula 1]
ΔE * = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2
The “light fastness retention” was calculated from the following formula by obtaining the above light fastness chromaticity (ΔE *) for each raw cotton before and after dyeing.
[Formula 2]
Lightfastness retention (%) = 100− (post-staining ΔE * −pre-staining ΔE *) / pre-staining ΔE * x100
In addition, as "dyeing" in light resistance retention evaluation, dyeing was performed by the following method without using a dye.

(Dyeing method)
Without using dye, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dyeing assistant (manufactured by Meisei Chemical Industry Co., Ltd., trade name: Disper TL) 0.5 g / A staining solution containing L was prepared.
Subsequently, the dyeing treatment was performed at 120 ° C. for 60 minutes with the bath ratio of the raw cotton and the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at 80 ° C. for 20 minutes at a bath ratio of 1:20, and after washing with water, dried raw cotton was obtained.

[Evaluation of dyed spun yarn]
(Dyeing of meta type wholly aromatic polyamide spun yarn and polyester spun yarn)
Cationic dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayacryl Blue GSL-ED (B-54)) 1.5% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent A dyeing liquid containing 0.5 g / L of a dyeing assistant (manufactured by Meisei Chemical Co., Ltd., trade name: Disper TL) was prepared as a dispersant.
Subsequently, for each of the meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn soft-wound in a cheese shape, a dyeing treatment was performed at 120 ° C. for 60 minutes with a bath ratio of the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at a bath ratio of 1:20 at 80 ° C. for 20 minutes, and after washing with water and drying, a dyed spun yarn was obtained.

(Dyeing rate of meta-type wholly aromatic polyamide spun yarn)
Dichloromethane having the same volume as the dyeing residual liquid was added to the dyeing residual liquid dyed with the meta-type wholly aromatic polyamide spun yarn to extract the residual dye. Subsequently, with respect to the extract, the absorbance at wavelengths of 670 nm, 540 nm, and 530 nm was measured, respectively, and the dye concentration of the extract was determined from the calibration curve of the above three wavelengths prepared from a dichloromethane solution with a known dye concentration in advance. The average value of the concentration was defined as the dye concentration (C) of the extract. Using the dye concentration (Co) before dyeing, the value obtained by the following formula was used as the dyeing rate (U).
Dyeing rate (U) = [(Co−C) / Co] × 100

(Discoloration evaluation)
Each of the dyed meta-type wholly aromatic polyamide spun yarn and polyester spun yarn was irradiated with a carbon arc fade meter at 63 ° C. for 24 hours, and each of the light-irradiated portion and the non-irradiated portion was used. The light fast discoloration (ΔE *) was obtained. As the light resistance change chromaticity (ΔE *), first, the diffuse reflectance in the -10-degree field of view is measured using the light source D65, and the lightness index L * value, the chromaticness index a *, b are obtained by normal calculation processing. * A value was calculated, and the obtained value was used to obtain the value according to the following formula in accordance with JIS Z-8730.
[Formula 3]
ΔE * = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2

<Example 1>
[Spinning liquid adjustment process]
20.0 parts by mass of polymetaphenylene isophthalamide powder having an intrinsic viscosity (IV) of 1.9 produced by an interfacial polymerization method in accordance with the method described in Japanese Patent Publication No. 47-10863 is placed at −10 ° C. It was suspended in 80.0 parts by mass of cooled N-methyl-2-pyrrolidone (NMP) to form a slurry. Subsequently, the suspension was heated to 60 ° C. and dissolved to obtain a transparent polymer solution.
To the polymer solution, 3.0% by mass of 2- [2H-benzotriazol-2-yl] -4-6-bis (1-methyl-1-phenylethyl) phenol powder (solubility in water: 0) .01 mg / L) was mixed and dissolved, and depressurized under reduced pressure to obtain a spinning solution (spinning dope).

[Spinning and coagulation process]
The spinning dope was spun from a spinning nozzle having a hole diameter of 0.07 mm and a hole number of 500 into a coagulation bath having a bath temperature of 30 ° C. The composition of the coagulation liquid was water / NMP = 45/55 (parts by mass), and was spun by discharging into the coagulation bath at a yarn speed of 7 m / min.

[Plastic stretching bath stretching process]
Subsequently, the film was stretched at a stretching ratio of 3.7 times in a plastic stretching bath having a composition of water / NMP = 45/55 at a temperature of 40 ° C.

[Washing process]
After stretching, the film was washed with a 20 ° C. water / NMP = 70/30 bath (immersion length 1.8 m), followed by a 20 ° C. water bath (immersion length 3.6 m), and then a 60 ° C. hot water bath (immersion length 5). 4m) and thoroughly washed.

[Dry heat treatment process]
The washed fiber was subjected to a dry heat treatment with a heat roller having a surface temperature of 280 ° C. to obtain a meta-type wholly aromatic aramid fiber.

[Physical properties of fibrils]
The physical properties of the obtained fibrils were a fineness of 1.7 dtex, a breaking strength of 2.9 cN / dtex, a breaking elongation of 52.0%, and a residual solvent amount of 0.08% by mass, showing good mechanical properties. Table 1 shows the physical properties of the obtained fibrils.

[Crimping and cutting process]
After imparting crimps to the fiber obtained through the crimper, raw fiber was obtained by cutting with a cutter into a short fiber of 51 mm.

[Dyeing process 1]
Cationic dye (product name: Kayacryl Blue GSL-ED (B-54), manufactured by Nippon Kayaku Co., Ltd.) 6% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dispersion A dyeing solution containing 0.5 g / L of a dyeing assistant (made by Meisei Chemical Co., Ltd., trade name: Disper TL) was prepared as an agent.
The obtained raw cotton was dyed for 60 minutes at 120 ° C. with a bath ratio of the raw cotton to the dyeing solution of 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at 80 ° C. for 20 minutes at a bath ratio of 1:20, and dyed cotton was obtained by drying after washing with water.

[Physical properties of dyed cotton, etc.]
The dyeing rate of dyed cotton was 91.2%, indicating good dyeability. The breaking strength of the dyed cotton was 2.9 cN / dtex. The results are shown in Table 1.

[Dyeing process 2]
Without using dye, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent, dyeing assistant (manufactured by Meisei Chemical Industry Co., Ltd., trade name: Disper TL) 0.5 g / A staining solution containing L was prepared.
The obtained raw cotton was dyed for 60 minutes at 120 ° C. with a bath ratio of the raw cotton to the dyeing solution of 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at 80 ° C. for 20 minutes at a bath ratio of 1:20, and dyed cotton was obtained by drying after washing with water.

[Light resistance retention]
The light fastness retention of the obtained raw cotton was 91%. The results are shown in Table 1.

[Production of spun yarn]
The meta-type wholly aromatic polyamide short fibers cut to 51 mm described above are passed through the cotton-cutting, carding, roving, spinning, and rewinding processes, and the spun yarn consisting only of the meta-type wholly aromatic polyamide short fibers (count: 30/2) and soft-wound into 1 kg of cheese.
Next, a polyester short fiber having a fineness of 1.3 dtex and a fiber length of 51 mm (trademark: “Tetron” (registered trademark) manufactured by Teijin Fibers Ltd.) is similarly applied to the cotton batter, cotton wool, roving, fine spinning, and rewinding steps. A spun yarn (count: 30/2) consisting only of polyester short fibers was produced and soft-wound into 1 kg of cheese.

[Dyeing process of spun yarn]
Cationic dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayacryl Blue GSL-ED (B-54)) 1.5% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, benzyl alcohol 70 g / L as a carrier agent A dyeing liquid containing 0.5 g / L of a dyeing assistant (manufactured by Meisei Chemical Co., Ltd., trade name: Disper TL) was prepared as a dispersant.
Subsequently, for each of the meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn soft-wound in a cheese shape, a dyeing treatment was performed at 120 ° C. for 60 minutes with a bath ratio of the dyeing solution being 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at a bath ratio of 1:20 at 80 ° C. for 20 minutes, and after washing with water and drying, a dyed spun yarn was obtained.

[Evaluation results of dyed spun yarn]
The dyeing rate of the meta-type wholly aromatic polyamide spun yarn was 93.1%. The meta-type wholly aromatic aramid fiber has a light fast discoloration (ΔE *) of 26.1, and a polyester spun yarn has a light fast discoloration (ΔE *) of 22.8. There was no difference and the result was good. The results are shown in Table 1.

<Example 2>
[Spinning liquid adjustment process]
85.48 parts of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) is placed in a reaction vessel equipped with a stirrer and a raw material inlet, and metaphenylenediamine (hereinafter abbreviated as MPDA) in this NMP. 4 parts were dissolved. Further, 156.9 parts of isophthalic acid chloride (hereinafter abbreviated as IPC) was gradually added to the solution while stirring to carry out the reaction. After stirring for 40 minutes from the start of the reaction, 57.1 parts of calcium hydroxide powder was added, and the reaction was terminated after stirring for another 40 minutes. When the polymerization solution was taken out from the reaction vessel, the polymerization solution was transparent and the polymer concentration was 16%.
To the polymer solution, 3.0% by mass of 2- [2H-benzotriazol-2-yl] -4-6-bis (1-methyl-1-phenylethyl) phenol powder (solubility in water: 0) .01 mg / L) was mixed and dissolved, and depressurized under reduced pressure to obtain a spinning solution (spinning dope).

[Spinning / coagulation process, plastic stretching bath stretching process, washing process, dry heat treatment process]
A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 1 except that the obtained polymerization solution was used as a spinning dope, the draw ratio in the plastic drawing bath was 3.7 times, and the surface temperature of the dry heat treatment step was 280 ° C. It was.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.7 dtex, a breaking strength of 2.7 cN / dtex, a breaking elongation of 50.0%, and a residual solvent amount of 0.08% by mass. Table 1 shows the physical properties of the obtained fiber.

[Crimping and cutting process]
The obtained fiber was crimped and cut in the same manner as in Example 1.

[Dyeing process 1]
The dyeing process 1 was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Physical properties of dyed cotton, etc.]
The dyeing rate was 92.4%, indicating good dyeability. The breaking strength of the dyed cotton was 2.7 cN / dtex. The results are shown in Table 1.

[Dyeing process 2]
The dyeing process 2 was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Light resistance retention]
The raw cotton obtained had a light resistance retention of 90%. The results are shown in Table 1.

[Production of spun yarn]
A meta-type wholly aromatic polyamide spun yarn was prepared under the same conditions as in Example 1 using the meta-type wholly aromatic polyamide short fibers cut to 51 mm.

[Dyeing process of spun yarn]
Each of the obtained meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn prepared in Example 1 was dyed in the same manner as in Example 1.

[Evaluation results of dyed spun yarn]
The dyeing rate of the meta-type wholly aromatic polyamide spun yarn was 92.6%. The meta-type wholly aromatic aramid fiber has a light fast discoloration (ΔE *) of 25.5, and a polyester spun yarn has a light fast discoloration (ΔE *) of 22.8. There was no difference and the result was good. The results are shown in Table 1.

<Example 3>
[Manufacture of fibrils]
The amount of 2- [2H-benzotriazol-2-yl] -4-6-bis (1-methyl-1-phenylethyl) phenol (solubility in water: 0.01 mg / L) added was 6.5 compared with the polymer. A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 2 except that the mass% was changed.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.7 dtex, a breaking strength of 2.6 cN / dtex, a breaking elongation of 47.8%, and a residual solvent amount of 0.07% by mass. Table 1 shows the physical properties of the obtained fiber.

[Crimping and cutting process]
The obtained fiber was crimped and cut in the same manner as in Example 1.

[Dyeing process 1]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed cotton, etc.]
The dyeing rate was 91.0%, indicating good dyeability. The breaking strength of the dyed cotton was 2.6 cN / dtex. The results are shown in Table 1.

[Dyeing process 2]
The dyeing process 2 was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Light resistance retention]
The light fastness retention of the obtained raw cotton was 93%. The results are shown in Table 1.

[Production of spun yarn]
A meta-type wholly aromatic polyamide spun yarn was prepared under the same conditions as in Example 1 using the meta-type wholly aromatic polyamide short fibers cut to 51 mm.

[Dyeing process of spun yarn]
Each of the obtained meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn prepared in Example 1 was dyed in the same manner as in Example 1.

[Evaluation results of dyed spun yarn]
The dyeing rate of the meta-type wholly aromatic polyamide spun yarn was 90.5%. Further, the meta-type wholly aromatic aramid fiber has a light fast discoloration (ΔE *) of 20.2, and a polyester spun yarn has a light fast discoloration (ΔE *) of 22.8. There was no difference and the result was good. The results are shown in Table 1.

<Comparative Example 1>
Highly hydrophilic methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate (solubility in water: 0.05 mg / L) as UV absorber A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 2 except that was used.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.7 dtex, a breaking strength of 2.6 cN / dtex, a breaking elongation of 47.8%, and a residual solvent amount of 0.10% by mass. Table 1 shows the physical properties of the obtained fiber.

[Crimping and cutting process]
The obtained fiber was crimped and cut in the same manner as in Example 1.

[Dyeing process 1]
The dyeing process was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Physical properties of dyed fibers]
The dyeing rate was 91.5%, indicating good dyeability. The breaking strength of the dyed cotton was 2.9 cN / dtex. The results are shown in Table 1.

[Dyeing process 2]
The dyeing process 2 was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Light resistance retention]
The obtained raw cotton had a light resistance retention of 52%, and the ultraviolet absorbent was highly hydrophilic, so that the ultraviolet absorbent was eluted during dyeing. The results are shown in Table 1.

[Production of spun yarn]
A meta-type wholly aromatic polyamide spun yarn was prepared under the same conditions as in Example 1 using the meta-type wholly aromatic polyamide short fibers cut to 51 mm.

[Dyeing process of spun yarn]
Each of the obtained meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn prepared in Example 1 was dyed in the same manner as in Example 1.

[Evaluation results of dyed spun yarn]
The dyeing rate of the meta-type wholly aromatic polyamide spun yarn was 91.6%. Further, the meta-type wholly aromatic aramid fiber has a light fast discoloration (ΔE *) of 31.2, and a polyester spun yarn has a light fast discoloration (ΔE *) of 22.8. The result was extremely large and color spots were produced when blended. The results are shown in Table 1.

<Comparative example 2>
[Spinning liquid adjustment process]
A spinning solution was prepared in the same manner as in Example 2 except that 2- [2H-benzotriazol-2-yl] -4-6-bis (1-methyl-1-phenylethyl) phenol powder was not added.

[Manufacture of fibrils]
Spinning / coagulation, plastic stretching bath stretching, and washing were performed in the same manner as in Example 2 to obtain an undried wet meta-type wholly aromatic polyamide fiber immediately after the washing step.

[Impregnation process of UV screening agent]
7 mL of methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate (water solubility: 0.05 mg / L) in 10 mL of methylene chloride The solution was poured into 100 mL of an aqueous solution in which 0.3 g of an emulsifier “EMCOL P10-59” was dissolved, with stirring. Stir until all the methylene chloride has evaporated, methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate (solubility in water: 0.05 mg / L ) Aqueous dispersion.
Next, the collected undried meta-type wholly aromatic polyamide fiber was put in 20 g of an aqueous dispersion and kept at room temperature for 1 hour with stirring. Subsequently, it was diluted with 100 mL of water, heated to the boiling point, and kept at that temperature for an additional hour. The removed fiber was washed with water and subjected to dry heat treatment with a heat roller at 310 ° C.

[Physical properties of fibrils]
The obtained fibrils had physical properties of a fineness of 1.7 dtex, a breaking strength of 2.6 cN / dtex, a breaking elongation of 47.8%, and a residual solvent amount of 0.03% by mass. Table 1 shows the physical properties of the obtained fibrils.

[Crimping and cutting process]
The obtained fiber was crimped and cut in the same manner as in Example 1.

[Dyeing process 1]
The dyeing process was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Physical properties of dyed fibers]
The dyeing rate was 91.0%. The breaking strength of the dyed cotton was 2.6 cN / dtex. The results are shown in Table 1.

[Dyeing process 2]
The dyeing process 2 was implemented similarly to Example 1 with respect to the obtained raw cotton.

[Light resistance retention]
The obtained raw cotton had a light resistance retention of 64%, and a large amount of the ultraviolet absorber was eluted. The results are shown in Table 1.

[Production of spun yarn]
A meta-type wholly aromatic polyamide spun yarn was prepared under the same conditions as in Example 1 using the meta-type wholly aromatic polyamide short fibers cut to 51 mm.

[Dyeing process of spun yarn]
Each of the obtained meta-type wholly aromatic polyamide spun yarn and the polyester spun yarn prepared in Example 1 was dyed in the same manner as in Example 1.

[Evaluation of spun yarn]
The dyeing rate of the meta-type wholly aromatic polyamide spun yarn was 90.5%. The meta-type wholly aromatic aramid fiber has a light fast discoloration (ΔE *) of 30.4, and the polyester spun yarn has a light fast discoloration (ΔE *) of 22.8. The result was extremely large and color spots were produced when blended. The results are shown in Table 1.

  The composite spun yarn of the present invention can suppress color spots caused by the difference in light fading between the polyester fiber and the meta-type wholly aromatic polyamide fiber. Therefore, the composite spun yarn of the present invention is extremely useful in fields where excellent heat resistance, flame resistance, and flame resistance are required, and is particularly suitably used as a heat-resistant protective clothing worn by firefighters during fire fighting operations. be able to.

Claims (5)

A composite spun yarn comprising a meta-type wholly aromatic polyamide fiber and a polyester fiber,
The meta-type wholly aromatic polyamide fiber contains an ultraviolet absorber having a solubility in water of less than 0.04 mg / L, the dyeing rate of the dyed fiber is 90% or more, and the light fastness retention before and after the carrier dyeing Is a composite spun yarn having a thread strength of 80% or more.   The composite spun yarn according to claim 1, wherein the amount of residual solvent of the meta-type wholly aromatic polyamide fiber is 0.1% by mass or less.   The composite spun yarn according to claim 1 or 2, wherein a blending amount of the ultraviolet absorber is 3.0 parts by mass or more and 6.5 parts by mass or less with respect to the entire mass of the fiber.   The composite spun yarn according to any one of claims 1 to 3, wherein the ultraviolet absorber is at least one selected from the group consisting of a salicylic acid ultraviolet absorber, a benzophenone ultraviolet absorber, and a benzotriazole ultraviolet absorber.   The mixing ratio of the meta-type aromatic polyamide fiber is 50 to 90% by mass with respect to the entire composite spun yarn, and the mixing ratio of the polyester fiber is 50 to 10% by mass with respect to the entire composite spun yarn. Item 5. A composite spun yarn according to any one of Items 1 to 4.